Buildup dielectric layer having metallization pattern semiconductor package fabrication method

ABSTRACT

A method of manufacturing a semiconductor package includes mounting and electrically connecting a semiconductor die to a substrate. The semiconductor die and the substrate are encapsulated to form an encapsulation. Via holes are laser-ablated through the encapsulation and conductive material is deposited within the via holes to form vias. A first buildup dielectric layer is formed on the encapsulation. Laser-ablated artifacts are laser-ablated in the first buildup layer. The laser-ablated artifacts in the first buildup layer are filled with a first metal layer to form a first electrically conductive pattern in the first build up layer. The operations of forming a buildup layer, forming laser-ablated artifacts in the buildup layer, and filling the laser-ablated artifacts with an electrically conductive material to form an electrically conductive pattern can be performed any one of a number of times to achieve the desired redistribution.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of Huemoeller et al., U.S. patentapplication Ser. No. 11/497,617, filed on Aug. 1, 2006 now U.S. Pat. No.7,548,430, issued on Jun. 16, 2009, which is a continuation-in-part ofScanlan et al, U.S. patent application Ser. No. 11/293,999, filed onDec. 5, 2005, entitled “SEMICONDUCTOR PACKAGE INCLUDING A TOP-SURFACEMETAL LAYER FOR IMPLEMENTING CIRCUIT FEATURES”, now U.S. Pat. No.7,633,765, issued on Dec. 15, 2009 which is a continuation-in-part ofHiner et al., U.S. patent application Ser. No. 10/806,640, filed on Mar.23, 2004, entitled “SEMICONDUCTOR PACKAGE INCLUDING TOP-SURFACETERMINALS FOR MOUNTING ANOTHER SEMICONDUCTOR PACKAGE”, now U.S. Pat. No.7,185,426, issued Mar. 6, 2007, which is a continuation-in-part ofHuemoeller, et al., U.S. patent application Ser. No. 10/138,225, filedon May 1, 2002, entitled “INTEGRATED CIRCUIT SUBSTRATE HAVINGLASER-EMBEDDED CONDUCTIVE PATTERNS AND METHOD THEREFOR”, now U.S. Pat.No. 6,930,256, issued Aug. 16, 2005, all of which are hereinincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to semiconductor packaging, andmore specifically, to a semiconductor package having blind vias forinterconnecting a metal layer atop the semiconductor package to internalcircuits of the semiconductor package.

2. Description of the Related Art

Semiconductor packages that provide mechanical mounting and electricalinterconnection of a semiconductor die are commonly provided in ballgrid array and land grid array configurations. A semiconductor die iselectrically connected to a substrate with a grid array terminalsdisposed on the “bottom” side of the semiconductor package and solderballs are attached for connection to a system substrate, typically aprinted circuit board (PCB) having lands located to attach the solderballs of the semiconductor package (referred to as ball grid array orBGA attach). Alternatively, conductive paste, a socket or “interposer”may be used to provide contacts between lands of the semiconductorpackage and lands on the system substrate (referred to as land gridarray or LGA connection).

The above-incorporated Parent U.S. patent application discloses atop-surface mounting terminal structure for attaching a secondsemiconductor package or die to the top of a first semiconductorpackage. While the packaging density of the combined devices isincreased, the location of the terminals is dictated by the design ofthe die or semiconductor package mounted on the first semiconductorpackage, which typically increases the interconnect density of thesubstrate in the first semiconductor package.

Also, it is often desirable to provide a metal shield cap atop asemiconductor package. Such shields are usually connected to a groundterminal or other reference voltage level by a through via extendingthrough the semiconductor package to one or more terminals.

Therefore, it would be desirable to improve upon the techniques of theabove-incorporated parent U.S. patent application to provide asemiconductor package and a method of manufacturing such a semiconductorpackage that facilitates stacking of grid arrays and other componentswhile reducing interconnect densities in the semiconductor package andincreases flexibility of design. It would further be desirable toimprove the techniques of the above-incorporated parent U.S. patentapplication to provide a semiconductor package and method of manufacturethat provides a metal shield cap without requiring additional throughvias.

SUMMARY OF THE INVENTION

In accordance with one embodiment, a method of manufacturing asemiconductor package includes mounting and electrically connecting asemiconductor die to a substrate. The semiconductor die and thesubstrate are encapsulated to form an encapsulation. Via holes arelaser-ablated through the encapsulation and conductive material isdeposited within the via holes to form vias.

A first buildup dielectric layer is formed on the encapsulation.Laser-ablated artifacts are laser-ablated in the first buildupdielectric layer. The laser-ablated artifacts in the first buildupdielectric layer are filled with a first metal layer to form a firstelectrically conductive pattern in the first buildup dielectric layer.The operations of forming a buildup dielectric layer, forminglaser-ablated artifacts in the buildup dielectric layer, and filling thelaser-ablated artifacts with an electrically conductive material to forman electrically conductive pattern can be performed any one of a numberof times to achieve the desired redistribution.

These and other features of the present invention will be more readilyapparent from the detailed description set forth below taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1H are pictorial diagrams depicting stages in preparation of asemiconductor package in accordance with an embodiment of the presentinvention;

FIGS. 2A-2C are pictorial diagrams depicting further stages in assemblyof a semiconductor package in accordance with another embodiment of thepresent invention;

FIG. 2D is a pictorial diagram depicting a semiconductor package inaccordance with another embodiment;

FIG. 3A is a pictorial diagram depicting a semiconductor package inaccordance with another embodiment of the present invention;

FIGS. 3B-3C are pictorial diagrams depicting stages in fabrication of asemiconductor package in accordance with yet another embodiment of thepresent invention;

FIG. 4 is a pictorial diagram of an assembly 400 during the fabricationof a plurality of semiconductor packages in accordance with oneembodiment of the present invention;

FIGS. 5, 6, 7, 8, and 9 are pictorial diagrams of the assembly of FIG. 4at further stages of fabrication in accordance with various embodimentsof the present invention; and

FIG. 10 is a pictorial diagram of a semiconductor package in accordancewith another embodiment of the present invention.

In the following description, the same or similar elements are labeledwith the same or similar reference numbers.

DETAILED DESCRIPTION

In accordance with one embodiment, referring to FIG. 4, a method ofmanufacturing a semiconductor package 410A includes mounting andelectrically connecting a semiconductor die 16 to a substrate 14C.Semiconductor die 16 and substrate 14C are encapsulated in an assemblyencapsulant 412 to form an encapsulation 12D, encapsulation 12D being aportion of assembly encapsulant 412.

Via holes are laser-ablated through encapsulation 12D and conductivematerial is deposited within via holes to form vias 22A, 22B, 22C.

Referring now to FIG. 5, a first buildup dielectric layer 502 is formedon encapsulation 12D. Laser-ablated artifacts 504 are laser-ablated infirst buildup dielectric layer 502.

Referring now to FIGS. 5 and 6 together, laser-ablated artifacts 504 infirst buildup dielectric layer 502 are filled with a first metal layer602 to form a first electrically conductive pattern 604 in first buildupdielectric layer 502. As shown in FIGS. 7 and 8, the operations offorming a buildup dielectric layer, forming laser-ablated artifacts inthe buildup dielectric layer, and filling the laser-ablated artifactswith an electrically conductive material to form an electricallyconductive pattern can be performed any one of a number of times toachieve the desired redistribution.

More particularly, in accordance with the present invention, asemiconductor package and a method for manufacturing a semiconductorpackage that include a metal layer formed atop a semiconductor packageencapsulation and connected to an internal substrate of thesemiconductor package by blind vias and/or terminals on the bottom sideof the encapsulation by through vias is presented.

While the exemplary embodiments depict ball grid array packages, it willbe understood by those skilled in the art, that the techniques inaccordance with the present invention can be extended to other types ofsemiconductor packages. The exemplary embodiments also show wirebond dieconnections within the semiconductor package, but it will be understoodthat any type of internal die and die mounting can be used within thesemiconductor package embodiments of the present invention.

Referring now to FIG. 1A, a semiconductor package 10A for forming asemiconductor package in accordance with an embodiment of the inventionand corresponding to a first illustrated step of manufacture isdepicted. Semiconductor package 10A is in the form of a ball grid array(BGA) or land grid array (LGA) package as is commonly known in the art,except that particular circuit features are positioned for providingvias to the top side of semiconductor package 10A in subsequentmanufacturing steps, so that connections may be made to features to beformed in subsequent steps.

Semiconductor package 10A includes a die 16 mounted to a substrate 14Athat includes lands 18 to which solder ball terminals may be attached orthat may be connected with a conductive paste to form a LGA mountedsemiconductor package. Encapsulation 12A surrounds die 16 and substrate14A, although substrate 14A may alternatively be exposed on a bottomside of semiconductor package 10A. Electrical connections 15, sometimescalled bond pads, of die 16 are connected to circuit patterns 17 onsubstrate 14A via wires 19, but the type of die mounting is notlimiting, but exemplary and other die mounting types may be used such asflip-chip die mounting. Additionally, while substrate 14A is depicted asa film or laminate-type mounting structure, lead frame and othersubstrate technologies may be used within the structures of the presentinvention.

Referring now to FIG. 1B, a first modification to semiconductor package10A that illustrates a second step in the manufacturing process to formsemiconductor package 10B is shown. Semiconductor package 10B includes aplurality of via holes 20A, 20B and 20C laser-ablated throughencapsulation 12A of FIG. 1A to form encapsulation 12B and substrate14B. While only three via holes are shown, many via holes may beprovided. The three via holes shown and as disclosed in theabove-incorporated parent U.S. patent application illustrate the threedifferent types of via holes that may be provided through control oflaser energy and exposure time. The first via hole type, illustrated asvia 20A, is fabricated by laser-ablating either completely throughsemiconductor package 10B or by laser-ablating through encapsulation 12Ato the top side of lands 18, so that a connection is provided from thetop side of semiconductor package 10B to the bottom side ofsemiconductor package 10B when the via is filled. If via 20A is ablatedcompletely through, then the corresponding land 18 is provided by thebottom surface of a via formed in hole 20A.

The next type of via hole is provided by laser-ablating throughencapsulation 12A to reach circuit pattern 17 so that connection may bemade through substrate 14A circuit patterns to die 16 electricalterminals, to lands 18 or both. The last type of via is provided bylaser-ablating through encapsulation 12A to reach electrical connections15 of die 16 so that direct connection to the circuits of die 16 can bemade from a piggybacked semiconductor package. Each of via holes 20A,20B and 20C is depicted as a via hole having a conical cross-section,which is desirable for providing uniform plating current density duringa plating process. However, via holes 20A, 20B and 20C may alternativelybe made cylindrical in shape if the advantage of cylindricalcross-section is not needed, for example if a conductive paste is usedto fill the via holes.

Referring now to FIG. 1C, a semiconductor package step 10C isillustrated. Conductive material applied within via holes 20A, 20B and20C to form conductive vias 22A, 22B and 22C through encapsulation 12Cand optionally substrate 14C for vias that are formed completely throughsubstrate 14C. The conductive material used to form vias 22A, 22B and22C may be electroplated or electro-less plated metal, conductive pastesuch as copper or silver epoxy compounds, or a low melting temperaturehigh-wicking solder alloy such as SUPER SOLDER.

Referring now to FIG. 1D, a next step of preparation of a semiconductorpackage 10D is illustrated. Channels 24 are laser-ablated in the topsurface of encapsulation 12C to form encapsulation 12D. Channels 24 maydefine circuit traces, terminals and other features that either providecomplete interconnection at the top surface of encapsulation 12D orconnect top-side features such as circuit traces and terminals to one ormore of vias 22A, 22B and 22C.

Next, as shown in FIG. 1E, channels 24 are filled to provide a metallayer 26 in a semiconductor package step 10E. Channels 24 may be filledby electroplating, filling with conductive paste with planarization ifrequired, or electro-less plating after treating channels 24 with anactivating compound. Further, the top surface of encapsulation 12D maybe overplated or over-pasted and then etched to isolate the circuitfeatures of metal layer 26.

After formation of metal layer 26, plating 28 may be applied as shown inFIG. 1F, yielding semiconductor package step 10F to protect the surfaceof metal layer and/or to prepare terminal areas defined by the topsurface of metal layer 26 for further processing such as wire bondattach or soldering.

Then, as shown in FIG. 1G, a solder mask 30 may be applied over the topof encapsulation 12D and portions of the metal layer 26, yieldingsemiconductor package step 10G. Solder mask 30 is useful in operationswhere reflow solder operations will be used to attach components tometal layer 26.

Solder balls 34 may be attached to bottom-side terminals 18 ofsemiconductor package step 10G to yield a completed ball-grid-array(BGA) package 10H that is ready for mounting on a circuit board or othermounting location. Alternatively, as with all depicted finalsemiconductor packages described herein below, the step illustrated inFIG. 1H may be omitted and bottom side terminals 18 plated, yielding aland-grid-array (LGA) package.

A “tinning” coat of solder 32 may be applied to the top side ofsemiconductor package 10H as illustrated by FIG. 2A to prepare formounting of top side components. The solder may be selectively appliedto only solder mounting terminal areas via a mask.

Next, components are mounted on the top side of semiconductor package10H and attached to metal layer 26 as illustrated in FIG. 2B. It will beapparent that the steps of attaching solder balls depicted in FIG. 1Hcan be performed after this step and that in general, various steps information of structures above encapsulation 12D may be performed atdifferent times. FIG. 2B illustrates mounting of another semiconductordie 16A that is wire-bonded via wires 19A to plated terminals of metallayer 26 and also mounting of discrete surface-mount components 36 viareflow soldering.

After attachment and interconnection of die 16A, as shown in FIG. 2C, asecond encapsulation 12E may be applied over die 16A, wires 19A and partof the top surface, sometimes called principal surface, of encapsulation12D to form a completed assembly.

Another alternative embodiment of the present invention is shown in FIG.2D. In FIG. 2D, another semiconductor package 38 may be ball-mounted toterminals formed on metal layer 26. The depicted embodiment provides forredistribution of terminals at virtually any position atop semiconductorpackage 10H2, since metal layer 26 can provide routing of circuits fromvias such as 22A-C to solder balls 34A at virtually any position atopsemiconductor package 10H2.

FIG. 3A illustrates another embodiment of the present invention thatincludes a metal layer 50 that provides a shield cap for semiconductorpackage 10I. Metal layer 50 may be electro-less plated atopencapsulation 12C (See FIGS. 1A-1C for formation steps prior to FIG. 3A)by applying a seed layer or may be paste screened to form metal layer50. Metal layer 50 may be solid layer, or a continuous pattern such as amesh screen to reduce separation and required metal to improve theplating process. Metal layer 50 is electrically connected to vias 22Aand/or 22B to provide a return path for the shield.

FIG. 3B illustrates another shield embodiment of the present invention.A shield cavity is laser-ablated in the top surface of encapsulation 12Eto form a semiconductor package step 10J having a cavity 24A. Cavity 24Ais then filled to form a metal shield layer 50A as shown in FIG. 3C.Metal layer 50A may be applied by paste screening or plating (andpossible subsequent etching process) to yield a shield that is containedwithin the sides of semiconductor package 10K.

FIG. 4 is a pictorial diagram of an assembly 400 during the fabricationof a plurality of semiconductor packages 410 in accordance with oneembodiment of the present invention. Referring now to FIGS. 1E and 4together, assembly 400 of FIG. 4 includes a plurality of semiconductorpackages 410 integrally connected together. Each semiconductor package410 of assembly 400 is substantially identical to semiconductor package10E of FIG. 1E, and semiconductor packages 410 are simply relabeled forclarity of discussion. Only the significant differences between assembly400 and semiconductor package 10E are discussed below.

Illustratively, assembly 400 includes an assembly substrate 414comprising a plurality of substrates 14C integrally connected together.Substrates 14C are substantially similar to substrate 14C illustrated inFIG. 1C.

Further, assembly 400 includes an assembly encapsulant 412, e.g., asingle integral layer of encapsulant encapsulating assembly substrate414, corresponding to a plurality of the encapsulations 12D illustratedin FIG. 1E. Assembly 400 of FIG. 4 is fabricated in a manner similar tothat discussed above with regards to semiconductor package 10E of FIG.1E, the discussion of which is herein incorporated by reference.

Referring now to FIG. 4, assembly 400 includes a plurality ofsemiconductor packages 410 as set forth above. Illustratively,semiconductor packages 410 are delineated from one another bysingulation streets 430. Semiconductor packages 410 include a firstsemiconductor package 410A, which is representative of all of thesemiconductor packages 410.

FIG. 5 is a pictorial diagram of assembly 400 at a further stage offabrication in accordance with one embodiment of the present invention.Referring now to FIG. 5, a first assembly buildup dielectric layer 502is formed on the principal surface 412P of assembly encapsulant 412.

Buildup dielectric layer 502 is an electrically insulating material.Illustratively, buildup dielectric layer 502 is epoxy molding compound(EMC) molded on principal surface 412P of assembly encapsulant 412. Inanother example, buildup dielectric layer 502 is a liquid encapsulantthat has been cured. In yet another example, buildup dielectric layer502 is a single sided adhesive dielectric layer which is adhered onprincipal surface 412P of assembly encapsulant 412. Although variousexamples of buildup dielectric layer 502 are set forth, the examples arenot limiting, and it is to be understood that other dielectric materialscan be used to form buildup dielectric layer 502.

Laser-ablated artifacts 504, e.g., openings, are formed in buildupdielectric layer 502 using laser ablation in one embodiment.Illustratively, laser-ablated artifacts 504 include via holes 506 andchannels 508. Laser-ablated artifacts 504 extend through buildupdielectric layer 502 and expose portions of metal layer 26.

FIG. 6 is a pictorial diagram of assembly 400 at a further stage offabrication in accordance with one embodiment of the present invention.Referring now to FIGS. 5 and 6 together, a metal layer 602 is formed andfills laser-ablated artifacts 504. More generally, laser-ablatedartifacts 504 are filled with metal layer 602, e.g., an electricallyconductive material such as copper. Illustratively, copper is plated andreduced to fill laser-ablated artifacts 504.

Filling laser-ablated artifacts 504 creates an electrically conductivepattern 604 within first buildup dielectric layer 502. Illustratively,via holes 506 and channels 508 (FIG. 5) are filled with metal layer 602to form electrically conductive vias 606 and traces 608, respectively,within first buildup dielectric layer 502.

Vias 606 and traces 608 are electrically connected to the pattern ofmetal layer 26. In one example, vias 606 are vertical conductorsextending through buildup dielectric layer 502 in a directionsubstantially perpendicular to the plane formed by a principal surface502P of buildup dielectric layer 502. Traces 608 are horizontalconductors extending parallel to the plane formed by a principal surface502P of buildup dielectric layer 502. Traces 608 extend entirely throughbuildup dielectric layer 502 as shown in FIG. 6. However, in anotherembodiment, traces 608 are formed in buildup dielectric layer 502 atprincipal surface 502P and a portion of buildup dielectric layer 502remains between traces 608 and assembly encapsulant 412. Although vias606 and traces 608 are set forth, in light of this disclosure, those ofskill in the art will understand that other electrically conductivestructures can be formed in electrically conductive pattern 604.Illustratively, solder ball pads or SMT pads are formed in electricallyconductive pattern 604.

Further, it is understood that the operations of forming a buildupdielectric layer, forming laser-ablated artifacts in the buildupdielectric layer, and filling the laser-ablated artifacts with anelectrically conductive material to form an electrically conductivepattern can be performed any one of a number of times to achieve thedesired redistribution. Such an example is set forth below in referenceto FIGS. 7 and 8.

FIG. 7 is a pictorial diagram of assembly 400 at a further stage offabrication in accordance with one embodiment of the present invention.Referring now to FIG. 7, a second buildup dielectric layer 702 is formedon principal surface 502P of first buildup dielectric layer 502.

Buildup dielectric layer 702 is an electrically insulating material. Inone embodiment, buildup dielectric layer 702 is formed of the samematerial and in a similar manner as buildup dielectric layer 502, and soformation of buildup dielectric layer 702 is not discussed in detail.

Laser-ablated artifacts 704, e.g., openings, are formed in buildupdielectric layer 702 using laser ablation in one embodiment.Illustratively, laser-ablated artifacts 704 include via holes, channels,solder ball pad openings and/or SMT pad openings. Laser-ablatedartifacts 704 extend through buildup dielectric layer 702 and exposeportions of metal layer 602.

FIG. 8 is a pictorial diagram of assembly 400 at a further stage offabrication in accordance with one embodiment of the present invention.Referring now to FIGS. 7 and 8 together, a metal layer 802 is formed andfills laser-ablated artifacts 704. More generally, laser-ablatedartifacts 704 are filled with metal layer 802, e.g., an electricallyconductive material 802 such as copper. Illustratively, copper is platedand reduced to fill laser-ablated artifacts 704.

Filling laser-ablated artifacts 704 creates an electrically conductivepattern 804. Illustratively, electrically conductive pattern 804includes electrically conductive vias, traces, solder ball pads, and/orSMT pads. Electrically conductive pattern 804 is electrically connectedto electrically conductive pattern 604 through buildup dielectric layer702.

FIG. 9 is a pictorial diagram of assembly 400 at a further stage offabrication in accordance with one embodiment of the present invention.Referring now to FIGS. 8 and 9 together, assembly 400 is singulatedalong singulation streets 430 thus forming a plurality of individualsemiconductor packages 410 as shown in FIG. 9. Each semiconductorpackages 410 includes an encapsulation 12D, a substrate 14C, a firstbuildup dielectric layer 902, and a second buildup dielectric layer 904.Encapsulation 12D is a portion of assembly encapsulant 412. Substrate14C is a portion of assembly substrate 414. First buildup dielectriclayer 902 is a portion of assembly buildup dielectric layer 502.Finally, second buildup dielectric layer 904 is a portion of assemblybuildup dielectric layer 702.

As shown in FIG. 9, for each semiconductor package 410, sides 14S, 12S,902S, 904S of substrate 14C, encapsulation 12D, first buildup dielectriclayer 902, second buildup layer 904, respectively, are flush with oneanother, i.e., are substantially coplanar and in the same plane.

Although the formation of a plurality of individual semiconductorpackages 410 using assembly 400 is set forth above, in light of thisdisclosure, those of skill the art will understand that semiconductorpackages 410 can be formed individually, if desired.

FIG. 10 is a pictorial diagram of a semiconductor package 1010 inaccordance with another embodiment of the present invention.Semiconductor package 1010 of FIG. 10 is similar to semiconductorpackage 410A of FIG. 9 and only the significant differences arediscussed below.

Semiconductor package 1010 includes a first buildup dielectric layer902A and a second buildup dielectric layer 904A. First buildupdielectric layer 902A and second buildup dielectric layer 904A ofsemiconductor package 1010 of FIG. 10 are similar to first buildupdielectric layer 902 and second buildup dielectric layer 904 ofsemiconductor package 410 of FIG. 9, respectively. Only the significantdifferences between buildup dielectric layers 902A, 904A and buildupdielectric layers 902, 904 are discussed below.

Referring now to FIG. 10, first buildup dielectric layer 902A entirelyencloses encapsulation 12D. More particularly, first buildup dielectriclayer 902A forms a cap that entirely encloses encapsulation 12D. Firstbuildup dielectric layer 902A is formed on and directly contacts theprincipal surface 12P and sides 12S of encapsulation 12D. Further, firstbuildup dielectric layer 902A contacts the upper surface of substrate14C directly adjacent encapsulation 12D.

First buildup dielectric layer 902A includes a horizontal portion 1002and sidewalls 1004. Horizontal portion 1002 contacts principal surface12P of encapsulation 12D. Sidewalls 1004 extend perpendicularly fromhorizontal portion 1002 to substrate 14C and contact sides 12S ofencapsulation 12D.

Similarly, second buildup dielectric layer 904A entirely encloses firstbuildup dielectric layer 902A. More particularly, second buildupdielectric layer 904A forms a cap that entirely encloses first buildupdielectric layer 902A. Second buildup dielectric layer 904A is formed onand directly contacts the horizontal portion 1002 and sidewalls 1004 offirst buildup dielectric layer 902A. Further, second buildup dielectriclayer 904A contacts the upper surface of substrate 14C directly adjacentfirst buildup dielectric layer 902A.

Second buildup dielectric layer 904A includes a horizontal portion 1022and sidewalls 1024. Horizontal portion 1022 contacts horizontal portion1002 of first buildup dielectric layer 902A. Sidewalls 1024 extendperpendicularly from horizontal portion 1022 to substrate 14C andcontact sidewalls 1004 of first buildup dielectric layer 902A.

Semiconductor packages 410, 1010 (FIGS. 9, 10) can be further processed.Illustratively, plating and solder masks similar to plating 28 of FIG.1F and solder mask 30 of FIG. 1G are formed. Solder balls are attachedto bottom-side terminals 18 to yield a completed ball-grid-array (BGA)package that is ready for mounting on a circuit board or other mountinglocation. Formation of solder balls is similar to formation of solderballs 34 as illustrated in FIG. 1H and discussed above and so is notrepeated here. Alternatively, solder balls are not formed, yielding aland-grid-array (LGA) package.

A “tinning” coat of solder may be applied to the metal layer 802 toprepare for mounting of top side components. The solder is similar tosolder 32 as illustrated in FIG. 2A and discussed above and so is notrepeated here. The solder may be selectively applied to only soldermounting terminal areas via a mask.

Next, components are mounted on the top surface of semiconductor package410, 1010 and attached to metal layer 802 in a manner similar to thatillustrated in FIGS. 2C, 2D, and so is not repeated here. By formingelectrically conductive patterns in successive buildup dielectriclayers, the pattern of vias 22A, 22B, 22C is redistributed into thedesired footprint (layout) of the top most electrically conductivepattern, e.g., electrically conductive pattern 804. Specifically, thefootprint of electrically conductive pattern 804 is optimized forattachment of component(s) on the top surface of semiconductor packages410, 1010. Conversely, the pattern of vias 22A, 22B, 22C is largelydictated by the layout of lands 18, circuit pattern 17 and electricalconductors 15.

The drawings and the forgoing description give examples of the presentinvention. The scope of the present invention, however, is by no meanslimited by these specific examples. Numerous variations, whetherexplicitly given in the specification or not, such as differences instructure, dimension, and use of material, are possible. The scope ofthe invention is at least as broad as given by the following claims.

1. A method of manufacturing a semiconductor package comprising:mounting a semiconductor die to a substrate; electrically connecting thesemiconductor die to a circuit pattern of the substrate; encapsulatingthe semiconductor die and the substrate to form an encapsulation;laser-ablating via holes through the encapsulation; depositingconductive material within the via holes to form vias electricallyconnected to the circuit pattern of the substrate; forming a firstbuildup dielectric layer on the encapsulation; forming laser-ablatedartifacts in the first buildup dielectric layer, wherein thelaser-ablated artifacts include one or more of via holes, channels, andpad openings; and filling the laser-ablated artifacts in the firstbuildup dielectric layer with a first metal layer to form a firstelectrically conductive pattern in the first buildup dielectric layer.2. The method of claim 1 wherein the filling the laser-ablated artifactscomprises plating and reducing copper.
 3. The method of claim 1 whereinthe first electrically conductive pattern in the first buildupdielectric layer is electrically connected to the vias.
 4. The method ofclaim 1 further comprising: forming a second buildup dielectric layer onthe first buildup dielectric layer; forming laser-ablated artifacts inthe second buildup dielectric layer; and filling the laser-ablatedartifacts in the second buildup dielectric layer with a second metallayer to form a second electrically conductive pattern in the secondbuildup dielectric layer.
 5. The method of claim 4 wherein the firstbuildup dielectric layer entirely encloses the encapsulation and whereinthe second buildup dielectric layer entirely encloses the first buildupdielectric layer.
 6. The method of claim 1 further comprising repeatedlyperforming the following operations: forming a buildup dielectric layer;forming laser-ablated artifacts in the buildup dielectric layer; andfilling the laser-ablated artifacts in the buildup dielectric layer witha metal layer to form an electrically conductive pattern in the buildupdielectric layer.
 7. The method of claim 1 further comprising: formingelectrically conductive features at a top surface of the encapsulation,the electrically conductive features being connected to the vias,wherein the first electrically conductive pattern being is electricallyconnected to the electrically conductive features.
 8. The method ofclaim 7 wherein the first buildup dielectric layer is formed at least onthe top surface of the encapsulation.
 9. The method of claim 7 whereinthe encapsulation has sides and the first buildup dielectric layer hassides that are substantially coplanar with the sides of theencapsulation.
 10. The method of claim 7 wherein the first buildupdielectric layer entirely encloses the encapsulation.
 11. Thesemiconductor package of claim 10 wherein the first buildup dielectriclayer comprises sidewalls in contact with sides of the encapsulation.12. The method of claim 11 wherein the sidewalls contact the substrate.13. The method of claim 7 wherein the first electrically conductivepattern comprises electrically conductive vias formed within the firstbuildup dielectric layer and extending in a direction substantiallyperpendicular to a principal surface of the first buildup dielectriclayer.
 14. The method of claim 7 wherein the first electricallyconductive pattern comprises electrically conductive traces formedwithin the first buildup dielectric layer and extending in a directionsubstantially parallel to a principal surface of the first buildupdielectric layer.
 15. The method of claim 7 further comprising: forminga second buildup dielectric layer on the first buildup dielectric layer;forming laser-ablated artifacts in the second buildup dielectric layer;and filling the laser-ablated artifacts in the second buildup dielectriclayer with a second metal layer to form a second electrically conductivepattern in the second buildup dielectric layer.
 16. The method of claim15 wherein the first buildup dielectric layer entirely encloses theencapsulation and wherein the second buildup dielectric layer entirelyencloses the first buildup dielectric layer.
 17. A method ofmanufacturing a semiconductor package comprising: mounting semiconductordies to an assembly substrate comprising substrates integrally connectedtogether; electrically connecting the semiconductor dies to circuitpatterns of the substrates; encapsulating the semiconductor dies and theassembly substrate to form an assembly encapsulation; laser-ablating viaholes through the assembly encapsulation; depositing conductive materialwithin the via holes to form vias electrically connected to the circuitpatterns of the substrates; forming a first assembly buildup dielectriclayer on the assembly encapsulation; forming laser-ablated artifacts inthe first assembly buildup dielectric layer; filling the laser-ablatedartifacts in the first assembly buildup dielectric layer with a firstmetal layer to form first electrically conductive patterns in the firstassembly buildup dielectric layer; and singulating the assemblysubstrate, the assembly encapsulation and the first assembly buildupdielectric layer to form the semiconductor package.
 18. The method ofclaim 17 wherein the semiconductor package comprises an encapsulation,the encapsulation being a portion of the assembly encapsulation.
 19. Themethod of claim 17 wherein the semiconductor package comprises asubstrate, the substrate being a portion of the assembly substrate. 20.The method of claim 17 wherein the semiconductor package comprises afirst buildup dielectric layer, the first buildup dielectric layer beinga portion of the first assembly buildup dielectric layer.